This study was driven by the stringent environmental legislation concerning the consumption and utilization of eco-friendly materials. Within this context, this paper aimed to examine the characteristics of starch and fibres from the Dioscorea hispida tuber plant to explore their potential as renewable materials. The extraction of the Dioscorea hispida starch and Dioscorea hispida fibres was carried out and the chemical composition, physical, thermal, morphological properties, and crystallinity were studied. The chemical composition investigations revealed that the Dioscorea hispida starch (DHS) has a low moisture t (9.45%) and starch content (37.62%) compared to cassava, corn, sugar palm, and arrowroot starches. Meanwhile, the Dioscorea hispida fibres (DHF) are significantly low in hemicellulose (4.36%), cellulose (5.63%), and lignin (2.79%) compared to cassava, corn hull and sugar palm. In this investigation the chemical, physical, morphological and thermal properties of the Dioscorea hispida fibre and Dioscorea hispida starch were examined by chemical composition investigation, scanning electron microscopy (SEM), particle size distribution, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and Fourier transform infrared (FTIR), respectively. It was found that Dioscorea hispida waste is promising alternative biomass and sustainable material with excellent potential as a renewable filler material for food packaging applications.
This study examines the effects of varying the concentrations of sorbitol (S) and glycerol (G) on the physical, morphological, thermal, and mechanical properties of Dioscorea hispida, starch-based films. In this context, the films of Dioscorea hispida starch were developed using solution casting technique with glycerol (G), sorbitol (S), and a mixture of sorbitol-glycerol (SG) as plasticizers at the ratios of 0, 30, 45, and 60 wt%. The films' moisture contents were increased when increasing the plasticizer contents. The tensile strengths were decreased, but elongations at break were increased; 7.38%-11.54% for G-plasticized films, 10.17%-15.76% for S-plasticized films, and 14.41%- 16.10% for SG-plasticized films with increasing plasticizer concentrations of the film samples. Varying plasticizer concentrations exhibited a minor effect on the S-plasticized film's thermal properties. Significant decrement in the glass transition temperatures of Dioscorea hispida starch films was observed when the plasticizer contents were raised from 30% to 60%. Significantly, the present work has shown that plasticized Dioscorea hispida starch can be considered a promising biopolymer for the applications of biodegradable films.
Dragon fruit, also called pitaya or pitahaya, is in the family Cactaceae. It is found in two genera: 'Selenicereus' and 'Hylocereus'. The substantial growth in demand intensifies dragon fruit processing operations, and waste materials such as peels and seeds are generated in more significant quantities. The transformation of waste materials into value-added components needs greater focus since managing food waste is an important environmental concern. Two well-known varieties of dragon fruit are pitaya (Stenocereus) and pitahaya (Hylocereus), which are different in their sour and sweet tastes. The flesh of the dragon fruit constitutes about two-thirds (~65%) of the fruit, and the peel is approximately one-third (~22%). Dragon fruit peel is believed to be rich in pectin and dietary fibre. In this regard, extracting pectin from dragon fruit peel can be an innovative technology that minimises waste disposal and adds value to the peel. Dragon fruit are currently used in several applications, such as bioplastics, natural dyes and cosmetics. Further research is recommended for diverging its development in various areas and maturing the innovation of its usage.
This study is focused on developing and enhancing the properties of durian peel fiber (DPF) reinforced thermoplastic cassava starch (TPCS) composites. The proposed DPF was extracted from agro-waste and incorporated into TPCS with various contents of DPF (10, 20, 30, 40, and 50 wt%) via compression molding. The mechanical and thermal characteristics of the fabricated composites were studied. The thermal properties of the biocomposite were improved with the addition of DPF, as evidenced by an increase in the material's thermal stability and indicated by a higher onset decomposition temperature. The integration of DPF into TPCS improved the biodegradation rate process of the composites. Besides, the results indicated that incorporating DPF in TPCS composites enhanced tensile and flexural properties, with a 40 wt% DPF content exhibited the highest modulus and strength. The tensile and flexural strengths of TPCS/DPF composites were raised significantly from 2.96 to 21.89 MPa and 2.5 to 35.0 MPa, respectively, compared to the control TPCS sample, as DPF increased from 0 to 40 wt%. This finding was consistent with Fourier-Transform Infrared (FT-IR) spectroscopy and scanning electron micrograph (SEM), which showed good interaction between DPF and TPCS matrix. The analysis revealed that DPF at a 40 wt% ratio was the best composition compared to the other ratio. Finally, based on improved results, DPF was identified as a potential resource of green reinforcement for the biodegradable TPCS matrix.
The potential of Hylocereus polyrhizus peel (HPP) as a new eco-friendly reinforcement for thermoplastic sago starch/agar composite (TPSS/agar) was investigated. The integration of HPP into TPSS/agar composite aimed to enhance its mechanical and thermal characteristics. The study employed Fourier transform-infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), and Differential Scanning Calorimetry (DSC), as well as mechanical, physical properties and soil burial testing to analyse the composites. The results showed a favourable miscibility between the matrix and filler, while at higher concentrations of HPP, the starch granules became more visible. The tensile and impact properties of the composites improved significantly after incorporating HPP at 20 wt%, with values of 12.73 MPa and 1.87 kJ/m2, respectively. The glass transition temperature (Tg) and initial decomposition temperature (Ton) decreased with the addition of HPP. The density of the composites reduced from 1.51 ± 0.01 to 1.26 ± 0.01 g/cm3 as the HPP amount increased. The environmental properties indicated that the composites can be composted, with weight loss accelerating from 35 to 60 % and 61 to 91 % by the addition of HPP in 2- and 4-weeks' time, respectively. The study demonstrates the potential of TPSS/agar/HPP composites as eco-friendly materials for various applications.